Mutations in aass-1 cause abnormal mitochondrial enlargement in C. elegans. (A) Representative images of Mito-GFP–labeled structures in the hypodermis of N2, yq170, and yq211 animals carrying yqIs157 at the indicated developmental stages. Bars, 5 µm. (B) Quantification of animals with abnormally enlarged mitochondria (area ≥12 µm2) as shown in A. 90 animals or more were scored for each genotype. Comparisons are between N2 and mutants. (C and D) Images of mtLS::GFP-labeled structures in gonad sheath cells (C) and muscle and intestinal cells (D) in the indicated animals carrying hqIs181. Bars, 5 µm. (E) Quantification of animals with an abnormally enlarged mitochondria (area ≥12 µm2) as shown in C and D. 90 animals or more were scored for each genotype. (F) Images of mitochondria labeled with TOMM-20::mCh and IMMT-1::GFP in the hypodermis of animals with the indicated genotypes. Bars, 5 µm. (G) Schematic representation of the aass-1 gene. Filled boxes represent exons, and thin lines indicate introns. The ok926 deletion and point mutations of aass-1 are indicated with red lines. (H) Comparison of C. elegans AASS-1 with human AASS. The wavy lines represent mitochondrial targeting sequences (MTSs). The deletion and point mutations in AASS-1 are indicated with a red line and asterisks, respectively. (I) Graphic description of mitochondrial lysine degradation. α-KG, α-ketoglutarate. For all quantifications, *, P < 0.05; **, P < 0.01; and ***, P < 0.001. Error bars represent SEM.
